Improvement in safety-valves



F W. RICHARDSON.

Safety-Valves.

Patented Sept. 10,1878.

N- PETERS. PHOTO L TNOGRAPHER UNITE STATES PATENT ,"F E'D w. RICHARDSON,or TROY, *nEw Y o-RK.

IMPROVEMENT IN sAFETY-vALvi-is.

Specification forming part of Letters Patent No. 207,820, datedSeptember 10, 1878; application filed August 9, 1878.

To all whom it may concern:

Be it knownithat I, FRED W ltrcnnnnson,

the valve is liable to stick, and thus fail toacof Troy, county ofRensselaer, and State of New York, have invented certain new and use fulImprovements in- Safet-y-Valves, of which the following is a full, clearand exact descrip tion, reference being had to the accompanyingdrawings, and to the letters of reference marked thereon. I j y Figure 1is a vertical section of my improved; safety-valve; Fig. 2, an elevationor exterior} view, and Fig. 3 a' plan or top view of the cap;

escape-opening B, from whiehth'e conductingand piston. Like letters inall the figures indicate corresponding parts. Y f My present inventionhas special relation to that class of valves denominated reactionaryspring-loaded safety-valves, such as the Richardson, Orme, Crosby,Cameron, and others.

The object of my invention is to adapt the safety-valve to be inclosedor covered by a casing, from which a pipe may conduct the escaping steamto any desired point or place to accomplish any particular purpose-as,for instance, to heat the feed-water, or to conduct steam. to a mufflerfor the purpose of getting rid of the obj ectionable noise of the steamas it escapes from the safety-valve, or toconduct the escaping steam tothe smoke-arch or other convenient place for a like purpose.

To this end my invention consists in balancing the safety-valve withinthe casing, and in certain new and useful arrangements or combinationsof parts, all of which will be hereinafter first fully described, andthen pointed out in the claims. 7

It is obvious that if a chamber or case were formed around an ordinarysafety-valve, or around any of those of the class hereinbeforementioned, and the steam should escape from the boiler into this chamberor case in such volume that the conducting-pipe could not properlydischarge it, a back-pressure would be formed in such chamber, whichwould tend to close or seat the safety-valve before it wouldsufficiently relieve the boiler of excess of steam. To obviate thisdifficulty it has heretofore been proposed to so incase the valve withinthe outer casing or chamber as that the escaping steam cannot come incontact with the head of the valve. Thisconstruction necessitates adouble casing, within the innerwall of which complish its properpurposes j and su'chcassemblageof parts is likewiseconsiderablycomplieated, expensive, and morefliableto get out of-orderthantheimproveddevicebelowdescribed.

'In order to illustrate the'priiiciples of'my invention, I havechosen anordinaryflti'chardson safety-valve, to which my, improvements areapplied, asrepresented .in the. drawings" A is the exteriorcasingor,chamb'er','having pipe leads toany desired point, andO isjthevalve-seat u on which valve D rests. E is a spindle, on which is secureda bearing-plate, F, for the spring Gr. At H is an annular collar,surrounding the spindle and abutting against the screw-cap H, whichcollar serves as a top bearing-plate for spring G, and. admits freeaccess of steam to the piston P, which is'attached to spindle E.

The screw-cap H forms a short cylinder for accommodation of piston P,and also operates to compress the spring G when desired,therebyaffording means for regulating the requisite load for the safety -valve.The piston P isheld in properworkin g position by means of a jamnut, u,upon the screw-threaded "section of spindle E, on which said pistonmaybe conveniently set and made fast at any desired point. The area ofpiston or disk P should be made equal to the area of valve D in theparticular class of safety-valves shown; and when this counterbalan cing-piston is employed in connection with other forms of safety-valves therelative areas of the two should be so adjusted that the pressure uponboth will be equal.

From the construction and arrangement shown, it is apparent that whensteam unseats valve D and enters chamber A the pressure upon the innerface of piston P will be equal to the pressure upon the top of valve D,and will therefore diminish the spring-load by an amount equal to thispressure, in consequence of which the back-pressure within the chambertending to reseat the valve is counterbalanced-or, in other words, thecombined effect of the spring-load and the downward pressure upon thevalve is only as great as would be that of the spring-load alone withoutthe interposition of the piston.

A similar result may be attained by attaching the piston or disk to aspindle, which is made a part of or which is rigidly connected with thesafety-valve. Under this latter construction the pressure upon the underside of the piston will be equal to that upon the top of the valve; andsince the upward pressure is directly opposed to the downward pressure,the former will counterbalance the efi'ect of the latter.

The improved construction obviates the necessity of the secondary orinterior casing hereinbefore alluded to, renders the action of thesafety-valve equally independent of backpressure, while the wholearrangement is simple, comparatively inexpensive, little liable to getout of order, any of the parts are easy of access for repairs oradjustment, and the whole possesses obvious mechanical advantages overany other previous form of device for similar purposes-which, it isbelieved,will recommend it for general use.

With respect to arrangements of pipes in connection with this incasedand counterbalanced valve, I desire to state that I propose to make aseparate application for patent therefor.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is-

1. In combination with a springloaded safety-valve of the characterherein specified,

a piston or disk adapted to relieve the valve of a pressure about equalin amount to the pressure of the steam upon said disk, substantially asand for the purpose set forth.

2. In combination with an incased safetyvalve, a spring bearing thereon,a movable piston or disk adapted to receive the pressur,e of steam, anda spindle connected with said disk and with the spring, the whole beingarran gedto operate substantially as explained.

3. The piston P, in combination with a reactionary spring-loaded andincased safetyvalve, substantially as set forth.

4. The combination of piston I, spindle E, screw-cap H, collar H, springGr, case A, and a reactionary safety-valve, substantially as shown anddescribed.

In testimony that I claim the foregoing I have hereunto set my hand inthe presence of two witnesses.

F. W. RICHARDSON.

Witnesses:

WORTH Oseoon, Gno. F. GRAHAM.

